how do you know when the auxillary battery needs to be replaced?
Transmission service requires a few special tools to pump fluid back into transmission as there is no dipstick or fill tube. I'd leave that to a pro to avoid any issues




I have a 2015 E63 and seems my trunk auxiliary battery dies every 2-3 years and I just saw that FCP sells the MB OEM replacement with same part number ($135 or about 25 bucks higher than MB wholesaler) with their lifetime warranty so next time this dies in 2-3 years it will be a free replacement.... thought I would share as I am sure every w212/e63 owner is out of warranty by now and gonna need one of these sooner or later.
https://www.fcpeuro.com/products/mer...mer-0009829308






